Simplified abstract

The Thames Estuary is home to many fish species that rely on healthy intertidal habitats. But these habitats have been damaged by urban growth and climate change. Projects are working to rebuild and restore them, but we still don’t fully know how well they help fish.

This study will look at how fish use these rebuilt and restored habitats, what they eat, and how water conditions affect them. The results will help make future restoration efforts more effective, supporting healthy fish populations and a stronger ecosystem.


Abstract

Estuarine ecosystems support some of the most biologically productive intertidal habitats, sustaining diverse fish communities through complex food webs and connectivity. However, human-induced pressures, including urbanisation, degradation, and climate change, threaten the ecological integrity of these habitats. The Thames Estuary (UK) has experienced significant historic habitat loss, impacting fish populations and ecosystem resilience. Although ongoing intertidal habitat creation and restoration efforts aim to address these issues, the ecological functions of these habitats remain insufficiently understood. This study seeks to fill this knowledge gap by investigating how fish utilise created (or engineered) and restored intertidal habitats, examining their trophic interactions, and assessing the role of connectivity in maintaining estuarine ecosystem function.

A multidisciplinary approach integrating traditional net-based sampling, environmental DNA (eDNA) analysis (including gut content metabarcoding/metagenomics), stable isotope analysis, and functional guild assessments will be used to evaluate species diversity, diet composition, and habitat quality. Environmental variables including salinity, temperature, turbidity and dissolved oxygen are incorporated to explore how physicochemical gradients and habitat characteristics influence fish distribution, foraging behaviour, trophic dynamics, and ecosystem functioning.

The findings will provide valuable insights to inform evidence-based restoration strategies, ensuring that habitat interventions enhance ecological resilience and sustain fish populations while improving connectivity in the Thames Estuary.


Example habitats

Stanford-le-Hope - Restored (Lower Thames Estuary)
Point Wharf - Created/Engineered (Middle Thames Estuary)
West Thurrock - Degraded (Middle Thames Estuary)
Syon Park - Natural (Upper Thames Estuary)


Interactive map


Environmental parameters measured in June 2025

Note: Dashed lines indicate the boundaries between the Lower, Middle, and Upper Thames Estuary.